Pilbara craton detrital

Ohmoto H. (1999) Redox state of the Archean atmosphere evidence from detrital heavy minerals in ca. 3,250-2, 750 Ma sandstones from the Pilbara Craton, Australia Comment. Geology 27, 1151 — 1152. 

Several lines of geochemical evidence support low to negligible concentrations of atmospheric O2 during the Archean and earliest Proterozoic, when oxygenic photosynthesis may have evolved. The presence of pyrite and uraninite in detrital Archean sediments reveals that the atmosphere in the earliest Archean contained no free O2 (Cloud, 1972). Although Archean-age detrital pyrites from South Africa may be hydrothermal in origin, Australian sediments of the Pilbara craton (3.25-2.75 Ga) contain rounded grains of... 

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